Periodic changes in behaviour in a child with pseudohypoparathyroidism.

A 9-year old prepubertal girl, gave a history of peri­ odic changes in behaviour of 16 months' duration. The parents described the changes in behaviour as follows. She becomes less communicative and less interactive with others and clinging to the mother. Vomiting or retching, poor food intake, disturbed sleep pattern, and sometimes feelings of fearfulness were other features. She was unable to give a descriptive account of her fears but referred to something or someone frightening her. Presence of abnor­ mal visual or auditory perceptual experiences could not be established. She refused to go to school, play or engage in any of her usual recreational activities during these epi­ sodes. The periodic changes were regular with each epi­ sode lasting 10 to 11 days and recurring at 13 to 14 day intervals. At the two ends of each episode, the change of behaviour was usually confined to only part of the day.